/**
 * Copyright © 2016-2025 The Thingsboard Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.thingsboard.mqtt;

import lombok.AccessLevel;
import lombok.Getter;
import lombok.Setter;

import java.util.regex.Pattern;

final class MqttSubscription {

    @Getter(AccessLevel.PACKAGE)
    private final String topic;
    private final Pattern topicRegex;
    @Getter
    private final MqttHandler handler;
    @Getter(AccessLevel.PACKAGE)
    private final boolean once;
    @Getter(AccessLevel.PACKAGE)
    @Setter(AccessLevel.PACKAGE)
    private volatile boolean called;

    MqttSubscription(String topic, MqttHandler handler, boolean once) {
        if (topic == null) {
            throw new NullPointerException("topic");
        }
        if (handler == null) {
            throw new NullPointerException("handler");
        }
        this.topic = topic;
        this.handler = handler;
        this.once = once;
        this.topicRegex = compileTopicRegex(topic);
    }

    private static Pattern compileTopicRegex(String topic) {
        StringBuilder sb = new StringBuilder();
        String[] parts = topic.split("/");

        for (int i = 0; i < parts.length; i++) {
            if (i > 0) sb.append("/");

            String part = parts[i];
            if (part.equals("+")) {
                sb.append("[^/]+");
            } else if (part.equals("#")) {
                sb.append(".*");
            } else {
                sb.append(Pattern.quote(part));
            }
        }

        sb.append("$"); // 完整匹配
        return Pattern.compile(sb.toString());
    }

    boolean matches(String topic) {
        return this.topicRegex.matcher(topic).matches();
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        MqttSubscription that = (MqttSubscription) o;

        return once == that.once && topic.equals(that.topic) && handler.equals(that.handler);
    }

    @Override
    public int hashCode() {
        int result = topic.hashCode();
        result = 31 * result + handler.hashCode();
        result = 31 * result + (once ? 1 : 0);
        return result;
    }

}
